This R13 grant proposal requests financial support for graduate students and postdoctoral fellows to attend the XXIII biennial meeting of the International Complement Society (ICS) in New York City from August 1st to 5th 2010. The meeting, known as the International Complement Workshop (ICW), is the premier international meeting dedicated to the advancement and dissemination of knowledge about the complement system, the primary humoral component of the innate immune system. It is anticipated that the 5-day meeting will attract over 400 participants, of which 50 to 60 will be graduate students and postdoctoral fellows. Moreover, it is expected that over 300 abstracts will be presented in 10 scientific sessions encompassing all aspects of complement research. Scientific topics will include: Complement Structure and Function, Complement Activation and Regulation, Interactions with Innate and Adaptive Immunity, Interactions with Pathogens, Deficiencies and Polymorphisms of Complement Proteins, Complement in Inflammatory and Autoimmune Diseases, Complement in Transplantation. In addition, there will be two keynote presentations, one clinical lecture and basic science talk. There are several objectives for this meeting which are as follows: (1) to provide a better understanding of the molecular basis for the activation and regulation of the complement system;(2) to better comprehend the complex interrelationships between complement system and the innate and adaptive arms of the immune system;(3) to bring together a diverse group of basic scientists from several disciplines (biochemistry, biophysics, cell biology, immunology, molecular biology, structural biology) together with clinicians from numerous specialties (allergy, clinical immunology, infectious diseases, pathology, rheumatology) to better understand the role complement plays in immune and infectious diseases;(4) to promote the development of new research approaches, identification of disease mechanisms and targets for therapeutics, and diagnostic tests and treatments;and (5) to educate, motivate and foster the next generation of scientists in the field of complement research. The requested grant funds will permit many young scientist trainees to participate in this meeting, and hopefully, both the ICS and the students/fellows will reap long-term benefits from this experience. This R13 proposal is a very worthwhile use of this grant mechanism.